(May 19, 2010) Nearly half of new-vehicle buyers in April and the first week of May this year purchased or leased new vehicles with 4-cylinder engines, according to Power Information Network (PIN) retail transaction data from J.D. Power and Associates. In relation to recent strong demand for smaller engines, Powergram asked Kevin Riddell, manager of Powertrain Forecasting, J.D. Power and Associates, to answer some questions about why 4-cylinder engines appear to be a more popular powertrain choice:
 
Q: Has the performance of 4-cylinder engines improved significantly?
 
A: Yes, it has. Thanks to increased use of technologies such as dual-variable valve timing, variable valve lift and direct injection, the engines are increasing in power and improving their fuel economy, although the revised fuel economy standards make better performance difficult to compare with older vehicles.

The market is also seeing an increase in turbocharging 4- cylinders, which can increase power so it is comparable to 6-cylinder engines.
 
Q: Fuel efficiency is becoming more important again with rises in gasoline prices. Is that the primary reason for selecting a 4-cylinder engine?
 
A: Fuel efficiency is definitely a key reason for selecting a 4-cylinder vehicle, both directly and indirectly. The growing number of B-Segment car models—such as the Honda Fit and Ford Fiesta—do not offer larger, 6-cylinder engines. Also, some manufacturers are replacing 6-cylinder engines with turbocharged 4-cylinders as a premium option in some models. This is a trend we see continuing in the coming years. The shift is largely driven in part by the increasing U.S. Corporate Average Fuel Economy (CAFÉ) standards. In these cases, the consumer has no choice.
 
At the same time, consumers are seeing models that only offered a V-6 in the past now include new 4-cylinder options. Examples of models with these engine choices include the redesigned 2010 Chevrolet Equinox compact crossover (CUV), Buick LaCrosse midsize CUV and the 2011/2012 Ford Edge midsize CUV.
 
Q: More midsize cars are being bought with 4-cylinder engines—Toyota Camry and Honda Accord—based on PIN data. Are there other major sub-segments where there has been an increase in these engine options?
 
A: Many of the unibody-based midsize new-vehicle segments, which are currently dominated by 6-cylinder models, will see at least some growth in the number of 4-cylinder applications. Near-term examples of this transition include the new 4-cylinder engine in the Toyota Sienna minivan; the Hyundai Santa Fe midsize CUV replacing a 2.7-liter V-6 with a 2.4-liter I-4 on the base models; the upcoming redesigned Ford Explorer midsize traditional utility, which will use an entry-level I-4; and the previously mentioned Ford Edge.
 
Luxury, or premium, car manufacturers such as Nissan (Infiniti brand) and BMW are considering adding 4-cylinder options in their compact premium conventional car models in the next few years. Also, as mentioned above, the Equinox and GMC Terrain in the compact CUV category have added 4-cylinder options, although that segment is already dominated by 4-cylinder models.
 
Q: What are forecasts for 4-cylinder sales as a percent of overall mix—vs. 6- and 8-cylinders, principally?
 
A: Our engine and transmission forecast projects 4-cylinder engines to make up 40% of North American light-vehicle production by 2013. Most attrition will happen with the 8-cylinder [engines] declining to a 27% share at the same time. Some 8-cylinder applications will be replaced by turbocharged 6-cylinder engines, similar to replacing normally aspirated V-6s with turbocharged 4-cylinder engines.
 
Q: Alternative powertrains use 4-cylinder engines. Can you add some insight?
 
A: While many alternative powertrain vehicles use 4-cylinders, not all do. There are many 6- and 8-cylinder flex-fuel models capable of burning E85 (ethanol) and/or gasoline. Diesel engines are found as 4-cylinders in many Volkswagen models, but 6-cylinder diesels are offered by Mercedes-Benz, BMW and Audi, and 8-cylinder diesels are found in heavy-duty pickups.  The majority of hybrid models are 4-cylinders, led by the Toyota Prius, which continues to account for 50% of U.S. hybrid sales.
 
Hybrids of electric motor and I-4 pairings have larger fuel economy improvements, since they are found on smaller vehicles. But there are other models offered by BMW, Mercedes-Benz, Chevrolet, GMC, Lexus and Toyota which use larger engines and electric motors to improve fuel economy as well. There are also other, lesser-known alternates in some areas, such as compressed natural gas vehicles, which use a modified combustion engine.